Many different types of memory devices are known for the storage of data. In selecting a memory device, the particular requirements for the data with which the memory device will be used are important. For example, several parameters such as the quantity of data, the required access time and the required storage time can play an influential role in memory device selection.
A memory device includes an array of memory cells with word lines extending along rows of the memory cells, and bit lines extending along columns of the memory cells. Memory cells are located at intersections of the word lines and bit lines. A memory cell can be connected to a semiconductor diode located between the memory cell and a substrate. The semiconductor diode prevents leakage currents from flowing between adjacent memory cells in the array. As smaller and smaller semiconductor elements are produced, problems arise due to their size. As the semiconductor diode becomes smaller, the thickness of the center insulating layer becomes sufficiently thin that electrodes can pass directly through the material, avoiding having to overcome the barrier energy of the insulator. This deters from the intent of having the diode present.